Lazurite


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Related to Lazurite: Lazarus

lazurite

[′laz·ə‚rīt]
(mineralogy)
(Na,Ca)8(Al,Si)O24(S,SO4) A blue or violet-blue feldspathoid mineral crystallizing in the isometric system; the chief mineral constituent of lapis lazuli.

Lazurite

 

(lapis lazuli), a mineral of the silicate subclass with a skeletal crystal lattice structure similar to that of sodalite. The chemical composition of lazurite is (Na, Ca)8[A1SiO4]6-(SO4 Cl, S)2. The mineral crystallizes in the isometric system, but crystals are rare. Most commonly it is granular or in compact masses of dark blue, violet, or greenish blue color. The hardness is 5.5–6.0 on Mohs’ scale, and the density is 2,380–2,420 kg/m3. Lazurite occurs in crystalline limestones along the contact boundary between the latter and alkaline syenites in association with pyrite, glaucolite, and other minerals. The largest known lazurite deposits are in Afghanistan (Badakhshan). In the USSR there are deposits in the vicinity of Lake Baikal and in the Tadzhik SSR. Lazurite is a valuable ornamental material and is also used in the preparation of the blue pigment ultramarine.

References in periodicals archive ?
Tenders are invited for Negotiations on the choice of the supplier of brick KRO for the object "Residential complex" Lazurite "at the intersection of Pobediteley-Narochanskaya str.
In wandering around I saw some amazing set-ups of lazurite from Afghanistan, alas not crystallized, but these are polished pieces weighing up to perhaps 50 kg and there were whole tables crammed with them
The famous Sar-e-Sang lapis lazuli ocality in Badakhshan Province, Afghanistan is best known, of course, for its lazurite, but good crystals of other species are found embedded in the distinctive, pyrite-flecked white marble of the locality.
Jewelry-industrial" and "industrial" materials range down a scale from lazurite, jadeite and nephrite at the top, through charoite, rhodonite, jasper and petrified wood, to items like "aventurine quartzite," "ophicalcite (serpentine/calcite)" and "agalmatolite (pyrophyllite/talc)," although, perhaps mercifully, the last three which merit separate chapters in the parade of chapters to follow are malachite, chalcedony and rhodonite.
com), who had e-mailed me beautiful photos of a fine lazurite crystal and one of the new brookite specimens from Pakistan.
These were collected at (or somewhere near) the classic Sar-e-Sang, Badakhshan locality revered for centuries for its lazurite crystals.
From Afghanistan, Bariand displayed choice crystals of lazurite.
This is the material which generally has been called winchite in recent years, being mainly known as dense beds of greenish white, opaque to translucent crystals hopelessly upstaged by the euhedral deep blue lazurite, sodalite, and lazurite/sodalite crystals that rest in the beds.
5 cm long, embedded in white marble, from the lazurite locality in the Kokcha Valley, Badakhshan, Afghanistan.
At the Main Show, Dudley Blauwet of Mountain Minerals International had even better lazurite and sodalite specimens, and some information about certain complexities in their composition(s).
The locality is the Kokcha Valley, Badakhshan: the place we've long known as the source of the world's only fine large lazurite crystals.
Still, the existence of elongated lazurite twins is quite probable.